All of this extra water that's being boiled requires energy, and it's been calculated that in one day of extra energy use from boiling kettles is enough to light all of the streetlights in England for a night.

Now, while in India, my parents always remind me to only drink boiled or bottled water, because unlike here in America, where I can just turn on a tap and easily get clean, potable water, in India, the water is often contaminated.